Poster Presentation Australian and New Zealand Society for Geriatric Medicine Annual Scientific Meeting 2025

Tau deposition in dementia with Lewy bodies: A multimodal clinical and imaging study  (119890)

Kai Sin Chin 1 , Paula Loveland 1 2 , Jenny Yu 1 3 , Leonid Churilov 3 , Vincent Dore 4 5 , Christopher Rowe 4 , Nawaf Yassi 1 3 , Rosie Watson 1 3
  1. Royal Melbourne Hospital, Parkville, VIC, Australia
  2. The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC
  3. The University of Melbourne, Parkville, VIC, Australia
  4. Austin Health, Heidelberg, VIC, Australia
  5. CSIRO, Clayton South, Victoria, Australia

Aims

Alzheimer’s disease co-pathology is common in dementia with Lewy bodies (DLB). Advances in tau positron emission tomography (PET) imaging enable in vivo assessment of tau pathology. Additionally, the CenTauR scale has been recently developed to harmonise tau PET quantification. We aimed to describe tau accumulation and its clinical associations in people with DLB using the second-generation tau PET tracer 18F-MK6240 as well as the newly developed CenTauR scale.

 

Methods

Forty-three participants with DLB (mean age 75±5 years, 86% male) underwent clinical assessment, amyloid-beta (Aβ) PET (18F-NAV4694) and tau PET (18F-MK6240). Aβ deposition was quantified using the Centiloid method (Aβ+≥25CL), whilst tau was measured using the CenTauR scale, with Tau+ defined as CenTauR≥14 in the temporoparietal (TP) and MTL+ defined as Tau- with CenTauR≥10 in the mesial temporal lobe.

 

Results

Twenty-four (56%) DLB participants were Aβ+, nine (20.9%) were MTL+ and four (9.3%) were Tau+. The majority of MTL+ (78%) and Tau+ (75%) were Aβ+. Overall tau burden was low (median tauTP 2.3 CenTauR [IQR -3.4, 4.5]). Higher CenTauRTP was associated with worse cognition (MMSE: rho -0.33, p=0.03; MoCA: rho -0.34, p=0.02). No significant associations were observed between tau deposition and other clinical features.

 

Conclusions

Approximately 1 in 5 patients with DLB demonstrated mesial temporal tau co-pathology, while 1 in 10 exhibited cortical tau based on assessment with 18F-MK6240. Higher cortical tau burden was associated with worse cognition. An improved understanding of Alzheimer’s disease co-pathology in DLB could broaden the therapeutic strategies available for patients with DLB in the future.